Geneva, Switzerland: CD4 testing has been firmly endorsed as the primary tool for identifying advanced HIV disease among individuals living with HIV, according to the World Health Organization (WHO).

The recommendation is included in the WHO 2025 guidelines on advanced HIV disease. Under these guidelines, advanced HIV disease in adults, adolescents, and children aged five years and above is defined as having a CD4 cell count below 200 cells per cubic millimeter. The WHO stated that advanced HIV disease remains the leading cause of AIDS-related deaths worldwide and continues to pose a major public health challenge. This persists even in regions with strong HIV testing coverage and treatment access, and despite progress toward achieving the global 95-95-95 targets.

The WHO further clarified that all children living with HIV under the age of five should be regarded as having advanced HIV disease at the time of diagnosis, unless they have been on antiretroviral therapy (ART) for more than one year and are considered clinically stable.

According to the global health body, the 2025 guidelines were developed to improve methods for identifying advanced HIV disease and to address poor health outcomes among people living with HIV who are discharged from hospitals.

In the updated guidance, CD4 testing is strongly recommended as the preferred approach for diagnosing advanced HIV disease. However, in regions where CD4 testing is not yet accessible, WHO clinical staging may be used as an alternative method for identifying advanced cases.

CD4 testing is advised for people living with HIV who are starting or restarting ART, returning to care after treatment interruption, experiencing confirmed or suspected treatment failure, or who are hospitalized, seriously ill, or clinically unstable.

The WHO also noted that CD4 testing can help detect treatment failure when viral load testing is unavailable. In addition, it can be used to determine eligibility for discontinuing co-trimoxazole preventive therapy and for initiating fluconazole prophylaxis.

For hospitalized individuals with HIV, the WHO highlighted the importance of interventions that support smooth transitions from inpatient to outpatient care and help prevent unnecessary hospital readmissions. These measures may include discharge planning, medication assessment, transitional care strategies, follow-up phone calls, home visits by healthcare workers or peer supporters, and personalized patient support.

The UN health agency also recommended the use of paclitaxel or pegylated liposomal doxorubicin as treatment options for people living with HIV who develop Kaposi sarcoma, a rare cancer affecting blood and lymph vessel linings.

The guidelines place strong emphasis on early diagnosis, rapid initiation of ART, and improved clinical care to lower illness rates and reduce deaths.

The WHO concluded that by adopting these recommendations, countries can slow disease progression, improve survival and treatment outcomes, and move closer to achieving global HIV elimination goals.